Vapor generator



Nov. 9, 1943. G. D. EBlssez'rsv Erm.. 2,333,544

VAPORv GENERATOR l Filed April 26,. 1941- 3 Sheets-Sheet 1 I F'ig. 2

wir" f ii:

George D Ebbes Will 'HRowandfINvENroRs Glen J Schaessow Nov. 9, 1943. G. DQEBBETS TAL 2,333,644

VAPQR 'GENERATOR `Filed April 26, 1941 5 Sheets--SheetY 2 ign/ft? Ebbecs I 014/6117 R5 Glen J. Schoessow INVENTO torneg Nov. 9, 1943. e. D. EBEE-rs ETAI.'

#non GENERATon m Sra/W ad s .b mw ..0 W O f oh, DRSc m? 0mm Gew@ Attorney ments of our invention.`

Patented Nov. 9, 1943 VAPOR GENERATOR George D. Ebbets, Kenilworth, and Will H. Ro-

wand, Plainfield, N. J., and Glen J. Schoessow, Barberton, Ohio, assignors to The Babcdck & Wilcox Company, Newark, N. J., a corporation of New Jersey Application April 26, 1941, Serial No. 390,486

15 Claims.

vision of a vapor generator of the character described in which the pressure parts are entirely bottom-supported, and a major portion of the upper drum loading is carried by a special arrangement and construction of furnace Wall tubes.

A further `object is the provision of a vapor generator of the general character described `which is especially adapted for use with a mechanical stoker as thefuelring means.

The various featuresV of novelty which characterize our invention are' pointed out with particularity in the claims annexed to Vandforming a part of this specification.` For a better understanding of the invention, its operating advantages and specific objects attained.V by its use, reference should behad to the accompanying drawings and descriptive matter in which, we have illustrated and described' several embodi- 'Of the' drawings:

Fig. 1 is a sectional elevation taken Yon the line I--I of Fig. 2 of asteam boiler constructed in accordance with the invention; u

Fig. 2 is a horizontal section taken 2-2 of Fig. 1; Y p.

Fig. 3 is a vertical section taken onthe broken section line 3-3 of Fig. `1; A 1 f Fig. 4 is a vertical section'taken on the line on the line I lI- of Fig. 1;

Fig. 5 is a vertical section taken on, the line 5-5 of Fig. 1; i

Fig. 6 is an enlarged view of a portion of the ,furnace side Wall tubes shown in Fig. 2;

construction; and s Figl0 is a horizontal section taken on the-line Iii-I0 of Fig. 9.

In the embodiment of the invention shown in Figs. 1-8, the vapor generator has a setting, substantially rectangular in horizontal and vertical cross-section, formed by a front wall I0, a rear wall I I, sideV walls I2 and I3, and a roof, I4. VWithin the setting are the pressure parts of the unit, the major portion of the steam generating surface being formed by a bank of small diameter tubes 20 extending between an'upper horizontal steam andwater drum 2| `and alaterally displaced lower water drum 22. AS shown, the drums 2| and 22 are laterally olTset a considerable distance, the drum 22 extending adjacent the rear Wall II and the drum 2| intermediate the front section of the unit. The tube bank 20 is formed by rows of dog leg tubes arranged parallel except fortheir end portions which are radially connected to the drums, the upper tube ends being confined to a portion of the drum 2| below the normal water level therein. In order to secure the maximum amount of steam generating surface Within the available space limitations, while maintaining devsirable circulation conditions therein at all ratings, the lower portions of the tubes 20 are arranged at an angle of approximately to the horizontal, while the upper tube portions are bent forwardly at an angle of approximately 32P to the horizontal.

The setting space containing the tube bank 2i) is ballied to provide a flow of heating gases transversely of the tubes in the bank through a series of gas passes arranged longitudinally of the tube bank. For this purpose a tile partition 24 is built up on the innermost tube row 20 at the furnace side of the bank the full distance between the drums and from the side wall I2 approximately half the length of the tube bank. Vertical transverse baliles 25 and 26 extend from the end of as indicated in Fig. 2, partly across the tube bank space to form serially connected transverse gas passes 21, 28, and 29. The two rearmost rows Zb of the tube bank have corresponding portions lining the rear wall I I and roof I4, and their intermediate portions-in the gas pass 29 staggered to provide adequate flow area therethrough to an inclined heating gas outlet nue 33 opening into the upper portion of the pass 29. Dampers 3l in the outlet i'lue 30 are operable to contro the draft through the unit. The lower water drum 22 rests on spaced supporting cradles 33 carried by the concrete foun- .dation 34,` thus providing .a bottom support for Top supportingof these pressure parts would not only increase the head room requirements of the unit, but also its cost of construction as well asl complicating the thermal expansion requirements in` operation.

In accordance with our invention, the steam and water drum 2| and upper section of the tube bank 23 are adequately supported without resulting in any increase in the head room requirements or any substantial increase in the cost of construction or number of structural parts than would otherwise be necessary, while at the same time simplifying the thermalexpansion requirements ofthe unit, by a specialv construction of some of the water tubes used for iiuid cooling the furnace side walls |2 and, |3"and the support means therefor. As shown, the portion of each side wall between the front wall l and tube bank is lined with a row of vertical water tubes 36. The tubes 36 are straight and'parallel substantially throughout their entire lengths, with their upper portions curved and radially connectedtothe end sections of the drum 2| below the normal water level therein. The lower ends of each row of tubes 36 are connected to a horizontal header 31 extending froma point adjacent the drum 22 to the outer side of the front wall I6; Supply tubes 38 connect the drum 22 to the adjacent ends of the headers 31. The drum 22 is anchored at its center. to provide symmetrical expansion.`

The previsions for, supporting each side water wall, as well as a corresponding portion of the weight of the drum 2|, upper section of the tube bank 26' and the contents thereof, comprise a pair of support castings 39 between each header Y31 and the foundation 34.

Each header is eX- pansibly secured to the corresponding support castings 39 by welding a plate 46 onto'thelower outer side of the header and bolting the plate through an expansion slot therein to the top.

ofthe support casting. The plate slot for the forward support permits movement of the header 31' axially thereof while. the rear plate .slot permitsboutward movement as well. Inaddition to the support. castings the four wall tubes 36a radja-k cent tothe vertical center line of the drum 2l 4are constructed to. yserve as support columns between the `drum and header.. As `shown in Fig. 6, the tubes 36St have they same Loutside diameter -as the remaining side wall tubes 36 with. a wall thickness approximately twice 'that of the remaining tubes 36, thus considerably increasing the compression .strength fof the tubes 36a. This arrangement of theithick walled tubes forms an effective means for :transmitting the gravity loading on the upper drum 12| :to the header ,31 and foundation, without increasing the `number of side walltu'bes required for wall protection. In

addition lto the support castings, the4 headers 3| have their ends adjacent the drum 22 `tied to f thatv drum :by ya supporting :arrangement which permits relative movement-of the `drinn-and headers parallel 13o-.the `drinn faxis, :but-prevents Yrelativemovement'cf these transversely of the 'drum axis. .As shownjn and 8 the .drum

Lfrom the lower water drum 22.

Ythe bridge wall 52.

side of the wall.

`the outer side of the tube row 60.

has a pair of angle brackets 4| welded thereon, each of which carries a pair of transversely spaced bars 42 on its upper side and between which a bar 43 on the underside of the corresponding header end slideably ts. With the described construction and arrangement, all of the pressure parts of the unit will be bottom-supported and thus all vertical'thermal expansion of the parts will be upward.

The described formation or the main tube bank vand drums, and arrangement of the side wall tubes, isparticularly adapted for a stoker fired unit, although broadly the boiler construction would also permit the use of other fuels, such as pulverized or granulated coal, oil or gas. In the construction illustrated, an underfeed type mechanical stoker extends through the front wall I0 with` its axis normal to the tube bank, the Stoker comprising a center feed and grate section 6.5 carried by bottom supports 46 and longitudinal walls 41, which are spaced from the bottom portions of the side walls |2 and |3 to form ash pits 48 at opposite sides of the stoker and below the dumping sections 49 thereof. Within the foundation is arranged an air blast tunnel 50 leading from a forced draft fan (not shown) to the center section of the stoker. A damper 5l at the eXit end of the tunnel 5B controls theair discharge from the fan.

The underfeed stokerextends rearwardly to a transverse bridge wa1l52 in front of and spaced The portion of the unit forwardly of the tube bank 20 and partition 24 is divided into a main furnace chamber 53 and an open pass 54 by a second partition` 55 formed by tile blocks arranged between a pair of tube rows 2li,c extending between the drums 2| and 22. The tubes 2l)c and partition 55 are constructed to form a vertically elongated restricted. gas exit 56k from the main furnace chamber 53, as shown in Figs. 2 and v3. Access to the .open pass is had by bending rearwardly the portions of a pair of tube 26 partition v55 adjacent the side wall I2 and opposite the third pass 29. The gas exit extends from the drum 2| t0y a point above the top of With this arrangement of the gas `exit 56 all of the products of combustion from the main furnace chamber will be required to enter the open pass 54 adjacent one end thereof and dow laterally therein to the entrance end of the first gas pass 21. As'shown in Fig. 1, the open pass 54 has an upwardly tapering c rosssection l'to provide-proper distribution of the heating gases ltherein and entering the tube bank 2l) substantially throughout the height of the gasl pass 21. The lower portions of the tubes 26@ between the bridge wall 52 and the drum 22 are substantially horizontal and spaced to permit free passage therethrough of ash separated from the heating gases in the open pass. The space betweenl the bridge wall and the drum 22 forms an ash pit 59 from which deposited ash can be removed through access doors in the side walls.

The front wall I6 is lined with a row of water tubes 66 extending from the drum 2| downwardly to a transversev header 6| at the outer A lesser number of supply tubes 62 are encased in the front wall I0 at The header 6| is connected .to and `supported from the ends of the headers 31 by short draintubes 63.

,water to the furnace water walls.

to one another 'and to the lower drum at the 'level of that drum.

The discharge from the riser tubes entering `thesteam and water drum 2| passes through corresponding cyclone type steam and water separa'tors 65 spaced along the length of the drum and which provide a highly effective separation of the entering steam and water before the steam `is 'discharged through the steam outlet connecbustion. of the fuel takes place'at a relatively rapid rate. All of the heating gases generated .must flow through the restricted gas outlet 56 at one side of the furnace chamber, thus creating a highly turbulent condition in the gases entering the fluid cooled open pass 54. Combustion of unburned fuel particles is rapidly completed in the open pass under these operating conditions, and the heating gases flow substantially horizontally therein to theY entrance end of the first pass 21, and serially through the gas vpasses 21, 28 and 29. Most of the tubes in the third gas pass 29 serves as downcomer tubes for theremaining portion of the bank, and the supply tubes 38 and 62 deliver adequate supplies of The vertical arrangement of substantiallyall of the tubes of the unit minimizes ash deposition thereon, and facilitates routine cleaning operations. The

steam generating unit disclosed is particularly 'adapted for central station and industrial units of relatively small capacity and low operating pressures. One installation of the unit illusstrated, for example, is designedfor a maximum isteaming capacity of 442,000A pounds of saturated steam per hour at a pressure of 150 psi.

While the steam generating unit illustrated in Figs. 1-8 is designed for the production of satu-` .rated steam only, it can be readily adapted for' the production of superheated steam, and such 4amodied construction is illustrated in Figs. 9 .and 10. As shown in these figures, the superheating surface is incorporated by eliminating the rear rows of generating tubes inthe first pass 21 and substituting nested rows of superheater .tubes extending along and substantially parallel to the generating tubes 20. The superheater lillustrated is of the .draining type having the lower ends of the tubes connected to superposed the drum 2l. While in accordance with the provisions of the statutes we have illustrated and described herein the best forms of our invention now known to us, those skilled in the art will understand that changes may be made in the form of the appara- 'tus disclosed without departing from the spirit of the invention covered by our claims, and that certain features of the invention may sometimes ybe used to advantage without a corresponding use of other features.

We claim: Y 41. A steam generator comprising Walls forming The vertical a setting containing pressure `parts including a lower transverse water drum, an upper transverse steam and `water drum laterally displaced ra substantial distance from said lower drum, and

an inclined bank of steam generating tubes connecting said drums, a furnace chamber at one side of and extending under the upper part of vsaid tube bank, means for bottom-supporting said upperdrum mainly consisting of a plurality of vertical water tubes extending substantially straight downwardly from said upper drum along opposite side walls of said furnace chamber, a header extending along each of said furnace side walls and connected to the lower ends of` said side Wall tubes, and means for bottom-supporting each of said headers.

2. A steam generator comprising walls forming a setting containing pressure parts including a lowervtransverse Water drum, an upper transverse steam and water drum laterally displaced a substantial distance from said lower drum, and an inclined bank of steam generating tubes connecting said drums, a furnace chamber at one side of and extending under the upper part of said tube bank, means for bottom-supporting said pressure parts comprising cradle means for bottom-'supporting said lower drum, a plurality of vertical drum-supporting water tubes extending substantially straight downwardly from said upper drum along opposite side walls of said furnace chamber, a horizontally arranged header extending along each of said furnace side walls adjacent the level of said lower drum and connected to the lower ends of said side wall tubes, and means for bottom-supporting each of said headers. v

3. A steam generator comprising walls forming a setting containing pressure parts including a lower transverse water drum, an upper transverse steam 'and waterdrum laterally displaced a substantial distance from said lower drum, 'and an inclined bank of steam generating tubes connecting said drums, a furnace chamber at one `side of and extending under the upper part of said tube bank, means for bottom-supporting said pressure parts comprising cradle means for 'bottom-supporting said lower drum, a plurality of vertical drum-supporting water tubes symmetrically arranged relative to the vertical axis of said upper drum and extending substantially straight Vdownwardly from said upper drum along 4opposite 'side walls of said furnace chamber, a

horizontally arranged header extending along l each of said furnace side walls and connected to a lower transverse water drum, an upper transverse steam and water drum laterally displaced from said lower drum, and an inclined bank of steam generating tubes connecting said drums,

`a furnace chamber at one side of and extending under the upper part of said tube bank, a row of vertically extending drum-supporting water tubes connected to said upper drum at opposite sides of the vertical axis of said upper drum and extending substantially straight downwardly along each of the opposite side walls of said furnace chamber, a horizontally arranged header extending along each of said furnace side walls adjacent the level of said lower drum and connected to the lower ends of said side wall tubes,

`Supply tubes connecting each header to said lower drum, means independent of said supply tubes for supporting one -end fof 11s-aid headers from said 1lower drinn: and separate support means for bot- .tom-supportingeach of said headers.

5.y A steam; generatory .comprising walls forming a settingcont-aining pressure parts including a flower transverse water'drum, an upper trans- '.verse steam and water .drum laterally displaced from said lower drum, andan inclined bank of nsteam. generatingv tubes connecting-said drums, a

`furnacelchamberl at'one .side of said tube bank,

famowzof vertically extending .Water tubes con- .nectedito-said upperdrum at opposite sides of :the =vertical axis thereof -and extending down- -iwardly along each of 4the opposite side walls of said vfurnace chamber, a horizontally arranged header extending along each .of said'furnace side `walls and connected tothelower ends of saidside wall tubes, the side wall tubes immediately adjacent the .vertical axisy of; said-upper drum having greater compression strength than the remaining :steam and water drum laterallydisplaced from .said lowerdnim, and an inclined bank of steam 'generating tubes connecting said drums, afurnace -chamberat one side f said tube bank, a row of vertically extending water tubes connected to said yupper drumat opposite sides of the vertical axis A.thereof and extending alongeach of the opposite iside walls of saidfurnace chamber, a horizontally :arranged header extending along each of said furnace side-walls and connected tothe lowerr ends of said side wall tubes, the side wall .tubes imme- -diately adjacent the vertical axis of said upper .drum having Vthe same outside Vdiameter as and .thicker walls than the remaining side wall tubes, ,and a support means for bottom-supportingeach yof said headers.

7. yA steam generator comprising walls-forming a setting containing pressure parts including .a lower transverse water drum, an upper transverse steam and water drum laterally displaced from said lower drum, and an inclined bank of steam generating tubes connecting said drums, a .furnace chamber at one side of said tube bank, .a row of vertically extending water tubes connected to said upper drum at opposite sides of the yvertical axis thereof and extending down- `wardly `along each of the opposite side walls of l.said furnace chamber, a horizontally arranged header extending along each of said furnace side `walls adjacent the level of said lower drum and connected to the lower ends of said side 'wall tubes, the side wall tubes immediately adjacent the vertical axis of said upper drum having greater compression strength than the remaining side wall tubes, supply tubes connecting said side wall headers to said -lower drum, means for supporting one end of said headers from said lower drum, a cradle support for said lower drum, and a support vmeans for bottom-supporting each of said headers.

8. A steam generator comprising walls forming a setting containing pressure parts including a lower transverse water drum, an upper transverse steam and water drum laterally displaced a substantial distance from said lower drum, and an inclined bank of steam generating tubes connecting said drums, a furnace chamber at one side .of and extending under the upper part of said tube band, a substantially vertical partition extending along the furnace 'side .of said tube bank Arand deiining a heating gas inlet to said, tube bank adjacent one end thereof, ai second substantially vertical partition at the .furnace side of `and lat- 'erally spaced from said first partition and defining therebetween an open pass openingltosaid vfurnace chamber adjacent the opposite en'd of 4said tube bank, a mechanical stoker in said fur- -nace chamber arranged normal to the longitudi- Ynal axis of said lowerdrunn a pluralityof ver- =tical water tubes connected to said'upperfdrum at opposite sides of the vertical axis thereof'a'nd v.extending substantially straight downwardh' from said upper drum along opposite Side walls vlof said furnace chamber, a horizontally arranged header extending along each ofA said furnace side walls adjacent the level of'said lower drum and vconnectedto the lower ends of said sidewall Itubes, 'and supply tubes connecting lsaid lower Adrum to saidside wall headers.

9. A steam generator comprising wallsforming ma setting ofv substantially rectanguiarhorizontal cross-section containing pressureparts includ- -ing alower transverse water drum adjacent the :rear `wall of vsaid setting, an upper transverse steam and water-drum displaced a substantial distance forwardly from said lower drum, and

;an inclined bank of steam generating tubes corrfnecting said drums,'the tubes in said generating `.bank 'having substantially their entire length formed by angularly arranged straight portions,

a furnace chamber arranged forwardly of and extending under the upper part of said tube bank, a substantially vertical partition extendingl along the furnace side of said tube bank anddefining a heating `gas 'inlet to said tube bank adjacent one end thereof, a second substantially vertical partition atlthe furnace side of and'forwardly :spaced from said first 'partition and Adefining -therebetween an open pass 'having a rrestril'sted opening to said furnace chamberadjacent the opposite end of said tube bank, a mechanical stoker for said furnace-chamber'arranged normal to the axis of said lower drum and 'supplying sfuel to the furnace chamber space under safd -upper part of said tube bank, andmeans for-bottom-supporting said pressure parts. n

10. A steam generator comprising walls form- 'inga setting of substantially,rectangular horizontal cross-section containing pressure parts includinga lower transverse water drum adjacent "the rear wall of said setting, an upper transverse steam and water drum displaced a substantial ,chamber adjacent the opposite end of said tube "bank, a plurality of vertical drum-supporting water tubes .connected to said upper drum at opposite sides of the vertical axis thereof and extending substantially straight downwardly from said upper drum along opposite side walls of said .furnace chamber, a horizontally arranged header extending along each of said furnace side Walls and connected to the lower ends of saidV side wall tubes, cradle means for bottom-supporting said lower drum, and means for bottom-supporting each of said headers.

11. A steam generator comprising walls forming a setting containing pressure parts including a lower transverse water drum, an upper transverse steam and water drum laterally displaced a substantial distance from said lower drum, and an inclined bank of bent steam generating tubes connecting said drums, a furnace chamber at one side of and extending under the upper part of said tube bank, a substantially vertical partition extending along the furnace side of said tube bank and dening a heating gas inlet to said tube bank adjacent one end thereof, a second substantially vertical partition at the furnace side of and laterally spaced from said first partition and dening therebetween an open pass having a restricted opening to said furnace chamber adjacent the opposite end f said tube bank, a mechanical stoker in said furnace chamber arranged normal to the axis of said lower drum, a plurality of vertical drum-supporting water tubes connected to said upper drum at opposite sides of the Vertical axis thereof and extending substantially straight downwardly from said upper drum along opposite side walls of said furnace chamber, a horizontally arranged header extending along each of said furnace side walls and connected to the lower ends of said side wall tubes, cradle means for bottom-supporting said lower drum, and means for bottom-supporting each of said headers.

12. A steam generator comprising walls forming a setting containing pressure parts including a lower transverse water drum, an upper transverse steam and water drum laterally displaced a substantial distance from said lower drum, and

' an inclined bank of steam generating tubes connecting said drums, a furnace chamber at one side of and extending under the upper part of said tube bank, means for bottom-supporting said upper drum mainly consisting of a plurality of vertical water tubes extending substantially straight downwardly from said upper drum along opposite side walls of said furnace chamber, a header extending along each of said furnace side walls and connected to the lower ends of said side wall tubes, means for bottom-supporting each of said headers, and a mechanical stoker arranged normal to the axis of said lower drum and supplying fuel to the furnace chamber space under the upper part of said tube bank.

13. A steam generator comprising walls forming a setting containing pressure parts includinga lower transverse water drum, an upper transverse steam and water drum laterally displaced a substantial distance from said lower drum, and an inclined bank of steam generating tubes connecting said drums, a furnace chamber at one side of and extending under the upper part of each of said headers, anda mechanical stoker in said furnace chamber arranged normal to the l axis of said lower drum and having grate sections extending under the upper part of said tube bank.

14. A steam generator comprising walls forming a setting of substantially rectangular horizontal cross-section containing pressure parts in- -cluding a lower transverse water drum adjacent the rear wall of said setting, and upper transverse steam and water drum displaced a substantial distance forwardly from said lower drum, and an inclined bank of steam generating tubes connecting said drums, a furnace chamber arranged forwardly of and extending under the upper part of said tube bank, a forwardly inclined partition extending along the furnace side of said tube bank and defining a heating gas inlet to said tube bank adjacent one end thereof, a second forwardly inclined partition at the furnace side of and forwardly spaced from said rst partition and dening therebetween an open pass having a restricted opening to said furnace chamber adjacent the opposite end of said tube bank, and a mechanical Stoker in said furnace chamber arranged normal to the axis of said lower drum and having grate sections extending under the upper part of said tube bank and partitions.

15. A steam generator comprising walls forming a setting, pressure parts including a lower transverse water drum, an upper transverse steam and water drum displaced a substantial distance forwardly from said lower drum, and an inclined bank of steam generating tubes connecting said drums, a furnace chamber arranged forwardly of and extending under the upper part of said tube bank, a forwardly inclined partition extending along the furnace side of said tube bank and defining a heating gas inlet to said tube bank adjacent one end thereof, a second forwardly inclined partition at the furnace side of and forwardly spaced from said first partition and defining therebetween an open pass, said second partition having an opening in the upper part thereof providing a restricted gas connection between said open pass and said furnace chamber adjacent the opposite end of said tube bank, and fuel burning lmeans for said furnace chamber arranged below the lower level of said restricted gas connection.

GEORGE D. EBBETS, WILL H. ROWAND, GLEN J. sCHoEssoW. 

